Liquid crystal display devices have features such as thinness and light weight, and are widely used, for example, as monitors (display devices) in various electronic devices, such as liquid crystal TVs, personal computers, mobile telephones, digital cameras, portable terminals, and particularly in mobile devices and the like.
In recent years, liquid crystal display devices having a liquid crystal display panel that uses active matrix drive have occupied the mainstream. A liquid crystal display panel has an element substrate and an opposing substrate, which are disposed to be mutually opposing and a liquid crystal layer sandwiched between the element substrate and the opposing substrate.
Of these, the element substrate is known as an active matrix substrate. A plurality of pixel electrodes that serve as the unit pixels of an image display are arranged in matrix fashion on the surface of the element substrate opposite the liquid crystal layer, thereby forming a rectangular display area for displaying images. Switching elements such as thin-film transistors (TFTs) are connected to each pixel electrode. It is possible for the switching elements to switch the drive voltage applied to each pixel electrode on and off.
A plurality of column control lines (signal lines) and a plurality of row control lines (scanning lines) are arranged in the display area of the element substrate so as to mutually intersect. The pixel electrodes and the switching elements are provided corresponding to the intersections of the plurality of column control lines with the plurality of row control lines.
Column control circuits (signal line drive circuits) electrically connected to the plurality of column control lines and row control circuits (scanning line drive circuits) electrically connected to the plurality of row control lines are provided in the peripheral area of the element substrate display area (referred to as the peripheral circuit area).
On the outside of the peripheral circuit area a terminal area in which a plurality of terminals are arranged in a line along an edge part of the element substrate and an interconnect area in which a plurality of interconnects are arranged between display area and the terminal area are provided. The plurality of terminals are provided in correspondence to each of the plurality of column control lines and the plurality of row control lines. The plurality of interconnects are arranged between the plurality of column control lines, and plurality of row control lines, and the plurality of terminals.
If column control circuits and row control circuits, which are described later, are formed monolithically, there are cases in which either interconnects directly leading out from the column control lines to the terminals or interconnects directly leading out from the row control lines to the terminals do not exist. Typically, the preferable application is a constitution in which row control circuits are monolithically formed and interconnects are lead out from the column control lines to the terminals.
Recently, there has been an increasing requirement for liquid crystal display panels that have higher resolution and are smaller. To meet this type of requirement, in an active matrix substrate, the area outside of the display area (called the frame) has been narrowed (by what is called frame narrowing).
Specifically, in an active matrix substrate, in order to meet such a requirement for frame narrowing, the column control circuits and row control circuits are simultaneously formed on the substrate (monolithically) as a base material of low-temperature polysilicon.
In an active matrix substrate, compared to the area occupied by the monolithic column control circuits and row control circuits and the like, the area occupied by the large number of interconnects that are led through the interconnect area is large, making it difficult to reduce the size of the interconnect area to accommodate frame narrowing. For this reason, in a conventional active matrix substrate, in order to accommodate frame narrowing, measures have been taken with regard to the width, the spacing, and the arrangement of the interconnects (refer to, for example, Patent References 1 and 2).